Slow the video for second language learners!
Adrian explains how to change the playback speed of a Youtube video. While he mentions why you might want to speed up the playback (ie. boring clip), second language teachers will be delighted to know that you can select 1/2 playback too. While the audio quality will vary depending on the original enunciation, it can make a rapid-fire French video much easier to grasp for FSL students. (ELL teachers could also find this useful.)
Tip: Don't forget to see if the clip has captions - sometimes the "on-the-fly" captions are laughable, but you might be lucky.
(merci ALP de m'avoir donner la suggestion!)